Interstitial lung diseases (ILDs) consist of idiopathic pulmonary fibrosis (IPF) and non-IPF ILDs. While pulmonary complications in IPF are relatively well-studied, there is a need for research on non-IPF ILDs, including connective tissue disease-associated ILDs (CTD-ILDs), and non-pulmonary outcomes of ILDs. We compare hospitalization, infection, and pulmonary/cardiac vascular event outcomes in patients with various ILDs.

We used data from 82 healthcare organizations between 2014 and 2023 on the TriNetX Research Network. In addition to IPF, we included patients with rheumatoid arthritis (RA)-ILD, systemic sclerosis (SSc)-ILD, myositis-ILD, hypersensitivity pneumonitis (HP) and pulmonary sarcoidosis. We employed propensity score matching (PSM) and assessed outcomes, including hospitalization, infection, and pulmonary/cardiac vascular events within one year of diagnosis.

A total of 66,771 patients met the inclusion criteria, with 15,228 diagnosed with IPF and 51,543 with non-IPF ILDs. Anti-fibrotic agents were used in 30.4% of IPF patients. IPF patients had higher risks of hospitalization, cytomegalovirus disease, aspergillosis, and pulmonary/cardiac vascular event compared to those with non-IPF ILDs. Within CTD-ILDs, RA-ILD was associated with increased risks of sepsis, bacteremia, and pneumonia, while SSc-ILD had higher risks of pulmonary vascular events. Myositis-ILD showed elevated risks of hospitalization and mortality compared to RA-ILD, whereas patients with HP and pulmonary sarcoidosis experienced more favorable outcomes.

We identified distinct risk profiles across ILD subtypes, with increased infection risks in RA-ILD and heightened pulmonary/cardiac vascular event risks in SSc-ILD and IPF. These findings emphasize the need for targeted surveillance/management strategies for different ILD subtypes.